Quebec researchers help develop novel technique for creating powerful, compact lasers

Researchers at the Institut national de la recherche scientifique (INRS) in Quebec are part of an international team that has demonstrated an innovative technique to increase the intensity of lasers, by compressing laser light pulses.

The technique, which the team successfully tested at the Advanced Laser Light Source facility at INRS’s Varennes campus, would make it possible to explore phenomena in quantum electrodynamics, a field of particle physics focused on how light and matter interact. The research also opens the door to commercializing high-power lasers that are significantly smaller and less expensive than current systems.

“With this technique, we’re starting to decrease the footprint, decrease the complexity of the laser,” team member and study co-author Jean-Claude Kieffer, professor at INRS’s Centre Énergie Matériaux Télécommunications, said in an interview. “It’s a very nice compromise between the complexity and the performance of the machine. And the costs will decrease by a factor of two or more.”

Ultra-short pulse, very high-intensity lasers have numerous potential applications: early detection of breast cancer; safer and more targeted cancer radiation therapy; highly precise surgery and other medical treatments; micro-machining next-generation materials in telecommunications and bioengineering; devices for security and defence; and in agriculture.

For example, Kieffer is collaborating with researchers at the University of Saskatchewan’s Phenotyping and Imaging Research Centre to develop advanced imaging technologies to view and understand plant-soil-microbe interactions. The work is aimed at increasing plant productivity, nutrient use efficiency and adaptability to stressors.

The international team included study lead author S. Yu. Moronov and other scientists at the Federal Research Center Institute of Applied Physics of the Russian Academy of Sciences and researchers at INRS, as well as Gérard Mourou, professor emeritus at École Polytechnique in Paris. Mourou, along with Donna Strickland from the University of Waterloo, received the Nobel Prize in Physics in 2018 for inventing a technique (“chirped pulse amplification”) later used to create ultra-short pulse, very high-intensity laser pulses.

The Russia-Canada-France research team, instead of increasing the energy of the laser to boost its intensity, sent a laser beam through an extremely thin and perfectly homogenous glass plate. This enabled the researchers to decrease the light pulse duration to only a few “femtoseconds” (a femtosecond is one quadrillionth of a second.)

“We show for the first time that you can manipulate relatively high energy. And you can get to very high power,” Kieffer said. The team’s paper, “Thin plate compression of a sub-petawatt Ti:Sa laser pulses,” made the cover of the journal Applied Physics Letters.

At the Advanced Laser Light Source facility, the researchers used three joules of energy with a 10-femtosecond pulse, to achieve an intensity of 300 terawatts (a terawatt is one trillion watts.) They plan to repeat the experiment using 13 joules of energy over five femtoseconds, for an intensity of three petawatts (a petawatt is 1,000 terawatts.)

“We would be among the first in the world to achieve this level of power with a laser that has such short pulses,” Kieffer said. He expects it will take three to five years to develop a commercial-scale laser system incorporating the team’s light pulse-compression technique.

The research team received financial support from the Natural Sciences and Engineering Research Council of Canada, the Canada Foundation for Innovation, the ministère de l’Économie, de la Science et de l’Innovation du Québec, and the Ministry of Science and Higher Education of the Russian Federation.

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